1. Field of the Invention
The present invention relates to an ultrasonic flow sensor and a temperature measuring method using the same.
2. Description of Related Art
Ultrasonic flow sensors are used for measuring a flow rate of a fluid flowing in piping. JP-A-2000-46607 discloses a clamp-on ultrasonic flow sensor which enables retrofitting on an outer peripheral surface of the piping, and a fitting thereof. The fitting enables the clamp-on ultrasonic flow sensor to be fixed to piping having various diameters.
JP-A-2000-46607 discloses embodiments in which first and second sensor units are arranged in a V-shape and in a Z-shape. In the V-shaped arrangement, the first and second sensor units are installed on a first mother line of piping at first and second positions apart from each other along a direction of longitudinal axis of the piping. In the V-shaped arrangement, the first sensor unit is disposed at the first position on the first mother line of the piping, and the second sensor unit is installed on the second mother line that opposes the first mother line in a diameter direction at the second position apart from the first position along the direction of the longitudinal axis of the piping.
The fitting disclosed in JP-A-2000-46607 is fixed to the piping with a band. The two sensor portions are accommodated in the fitting for the V-shaped arrangement. In other words, the fitting for the V-shaped arrangement disclosed in JP-A-2000-46607 is configured to position the first and second sensor units at positions apart from each other along the direction of the longitudinal axis of the piping with a single fitting. The fitting in which the two sensor portions are accommodated is fixed to the piping with the band, so that the first and second sensor units are arranged in the V-shape.
A single sensor unit is accommodated in the fitting for the Z-shaped arrangement. Two of such fittings are provided and each fitting is fixed to the piping with a band. The first fitting is then positioned at the first position on the first mother line of the piping, and the second fitting is positioned on the second mother line opposing the first mother line in the diameter direction at the second position apart from the first position along the direction of the longitudinal axis of the piping, so that the first and second sensor units are arranged in the Z-shape.